From: | "Eric G(dot) Miller" <egm2(at)jps(dot)net> |
---|---|
To: | pgsql-general(at)postgreSQL(dot)org |
Subject: | Re: Implicit row locking during an UPDATE |
Date: | 2001-05-25 04:25:43 |
Message-ID: | 20010524212543.A5353@calico.local |
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Thread: | |
Lists: | pgsql-general |
On Fri, May 25, 2001 at 02:23:50AM -0000, Dr. Evil wrote:
>
> I'm still not understanding this, and it's vitally important to the
> project I'm working on, so I have a question:
>
> >From my understanding, this:
>
> UPDATE account SET value = 10 WHERE number = 99;
>
> actually implies all of this:
>
> BEGIN;
> SELECT value FOR UPDATE FROM account WHERE number = 99;
> UPDATE account SET value = 10 WHERE number = 99;
> COMMIT;
> END;
>
> Is this correct? If so, there's something I don't understand.
No. Maybe you want to read the manual. Specifically look at
transaction isolation level under MVCC. Hmm, SET TRANSACTION ISOLATION
LEVEL doesn't seem to be taking in 7.1.1... Is that a bug? Guess the
only way to be sure is to use the transaction semantics above...
--
Eric G. Miller <egm2(at)jps(dot)net>
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